Mirrors have been in existence for years and have been used in interior building applications such as, for example, in bathrooms, as decorations, etc.; for exterior applications such as, for example, in concentrating solar power (CSP) and concentrating photovoltaic (CPV) applications, as well as in secondary reflector panels (SRPs); as well as handheld vanity and a host of other products. Mirrors generally are either (a) first surface mirrors, where the mirror coating is provided between the viewer and the supporting glass substrate, or (b) second surface mirrors, where the supporting glass substrate is interposed between the viewer and the mirror coating. See, for example, U.S. Pat. Nos. 7,276,289 and 7,678,459; U.S. Publication Nos. 2006/0077580; 2007/0178316; 2008/0073203; 2008/0164173; 2010/0229853; 2011/0176212; 2011/0176236; and 2012/0087029. The entire content of each of these patent documents is hereby incorporated herein by reference.
Many second surface mirrors include silver-based reflecting layers. Silver is highly reflective in the visible and infrared ranges, therefore making it a good choice from a total reflectance perspective.
Unfortunately, however, silver is quite expensive. It also is not particularly durable and, for example, is subject to corrosion when exposed to even building interior environments. Durability problems can be overcome with silver-inclusive mirrors, however, by applying one or more layers of protective paint. Yet these paints are sometimes expensive and, at a minimum, inject time delays in the process because they need to be coated and dried and sometimes re-coated and re-dried. Wet coating techniques also are “messy” and potentially hazardous to humans, especially where “heavy metals” are used.
Thus, it will be appreciated that there is a need in the art for improved mirrors and/or methods of making the same.
In certain example embodiments of this invention, a mirror is provided. A multilayer thin film coating is supported by a substrate. The multilayer thin film coating comprises, in order moving away from the substrate: a first silicon-inclusive layer, a metallic or substantially metallic layer comprising aluminum, an optional layer comprising Ni and/or Cr in direct contact with the metallic or substantially metallic layer (e.g., comprising aluminum), and a second silicon-inclusive layer in direct contact with the layer comprising Ni and/or Cr. A protective paint is wet-applied directly over and contacting an outermost layer of the multilayer thin film coating, with the protective paint being applied to ensure a post-cure density of at least 5 (and more preferably at least 10, with an example of 35) grams per square meter. The protective paint is cured (e.g., using at least one UV radiation source). The protective paint, following the curing, is adapted to survive seven day exposure to an 85 degree C. temperature at 85% relative humidity, as well as seven day exposure to a 49 degree C. temperature at 100% relative humidity.
In certain example embodiments of this invention, a method of making a coated article is provided. A coating comprising at least the following layers are sputter-deposited on a glass substrate in the following order: a first silicon-inclusive layer, a metallic or substantially metallic layer (e.g., comprising aluminum), and a second silicon-inclusive layer. A protective paint is wet-applied directly over and contacting an outermost layer of the coating, with the protective paint being curable in less than 2 seconds of exposure to a UV radiation source. The protective paint is cured using at least one UV radiation source. The protective paint is wet-applied and cured at a line speed of greater than 7 meters per minute.
In certain example embodiments of this invention, a method of making mirrors is provided. The method includes, for example, receiving, at a fabricator location, a coated article made in accordance with one of the methods described herein; and cutting the coated article into pieces of one or more respective desired sizes in making the mirrors.
In certain example embodiments of this invention, a coated article is provided. A glass substrate supports a sputter-deposited coating. The coating comprises at least the following layers in the following order: a first silicon-inclusive layer, a metallic or substantially metallic layer (e.g., comprising aluminum), and a second silicon-inclusive layer. A protective paint is provided directly over and contacting an outermost layer of the coating, with the protective paint being curable in less than 2 seconds of exposure to a UV radiation source and at a line speed of greater than 7 meters per minute. The protective paint, after curing, is adapted to survive seven day exposure to an 85 degree C. temperature at 85% relative humidity, as well as seven day exposure to a 49 degree C. temperature at 100% relative humidity, with no evidence of delamination of the protective paint and no evidence of deterioration of the coating.
The features, aspects, advantages, and example embodiments described herein may be combined to realize yet further embodiments.